1. Field of the Invention
The present invention relates to a wireless transmitting and receiving mechanism, and more particularly, to a wireless transceiver apparatus that shares an antenna module.
2. Description of the Prior Art
In a wireless communication system, a design of a transmitting/receiving switch (T/R switch) is mainly based on signal insertion loss during signal transmitting, signal isolation between a transmission signal and a reception signal and power handling capability. In practice, no matter whether the T/R switch is realized utilizing a ready-made product or other manner, the cost and the circuit board complexity should be taken into consideration. Therefore, in recent years, with the development of semiconductor process and the requirement of the cost, more and more products aim at having a power amplifier and a T/R switch integrated into one chip simultaneously. Regarding most of the designs having the T/R switch integrated therein, the principle thereof is to respectively control if a signal path of a transmitter end or a receiver end is conductive to determine a working mode. Please refer to FIG. 1, which is a circuit diagram illustrating a conventional apparatus 100 realized under the current technology for sharing an antenna module. The apparatus 100 includes two T/R switch components 101A and 101B, wherein the switch component 101A is coupled to the antenna module 105 and a power amplifier 110 (which is a circuit within the transmitter end), and the switch component 101B is coupled to the antenna 105 and a low-noise amplifier 115 (which is a circuit within the receiver end). The current technology utilizes a signal S_TR to control if the switch components 101A and 101B are conductive, wherein one of the signal paths has an inverter to make conductive statuses of the two switch components 101A and 101B different from each other.
However, since the transmission signal/reception signal will pass through the switch component 101A/101B, the parasitic effects resulted from the complementary metal-oxide-semiconductor (CMOS) process will still let the signal bear a certain loss even if the other working mode (e.g., a transmission mode) is disabled. As a result, the gain and linearity of the signal would be affected. The current method tries to decrease the signal leakage on the signal path, or change the parasitic resistance value of the substrate in a transistor. However, the significant effect of this conventional method is the greatly increased chip area. Thus, this method is only applicable to a circuit that transmits and receives narrowband signals. Therefore, a body floating technique is proposed to improve the power handling capability of the T/R switch. Since the power handling capability requires accurate control, an extra model for describing the power has to be developed, which increases the design time inevitably.